With the continuous improvement of people's living standards, a laundry machine only having the washing function is already unable to meet people's requirements, and the laundry machine is required to have a drying function or to be equipped with a dryer to dry clothes, shoes, hats or other stuffs after these stuffs are washed. A washer-dryer or a laundry dryer generally includes the following drying modes: an electrical-heating water condensation type drying system, an electric-heating wind condensation type drying system, and a heat pump heating type drying system using evaporator condensation and condenser heating. Compared with the first two drying modes, the heat pump heating type drying system uses a heat pump for drying, which is relatively energy-saving, thus has a wide market application prospect.
A typical heat pump washer-dryer is disclosed in a Chinese Patent Application No. CN 102286872A published on Dec. 21, 2011, which includes a drum, a heat pump system, a drainage pump, and etc . . . The heat pump system includes a compressor, an evaporator and a condenser which are connected via pipelines. Components of the heat pump system including the compressor, the evaporator and the condenser are arranged at the bottom of the heat pump washer-dryer. Since the bottom of the heat pump washer-dryer generally has a large available space, it is a conventional design in the industry to arrange the heat pump system at the bottom of the heat pump washer-dryer. However, in this case, it is inconvenient to discharge water.
Therefore, a technical problem to be addressed urgently in the field is to design a drying system and a laundry drying device, which have a good energy efficiency and is convenient to discharge condensate water, under the circumstance of space being limited.